This invention relates generally to a fever thermometer, and more particularly, to a thermometer that may be adhesively applied to the skin of the human body and which indicates the body temperature.
Reference is made to U.S. Pat. Nos. 3,661,142 and 4,030,482 for disclosure of thermometers in the same general art as this invention in which the thermometers utilize layers of encapsulated liquid crystals that change colors in response to changes in temperature within a predetermined temperature range to indicate the skin temperature of the body. As is conventional, these thermometers use a flexible backing web of plastic film or the like with a pressure-sensitive adhesive applied thereto so that the thermometer may be readily adhered to the skin.
In those fever thermometers of the type disclosed in U.S. Pat. No. 4,030,482, the liquid crystal indicators are initially of a color to compliment the background color applied to the flexible backing web so that the numerical display areas are substantially invisible at temperatures below a minimum threshold temperature of the indicator having the lowest temperature range. As a result, when such fever thermometer is applied to the skin under usual ambient temperatures, the attitude of the numerical display areas is not known or is not readily discernible. Accordingly, the thermometer may be adhesively applied with the attitude of the numerical display areas such that they cannot be easily read when they are made visible at temperatures within the responsive temperature ranges of the liquid crystal indicators. In such event, the thermometer may have to be removed and reapplied until the desired attitude is achieved.